Cartridge detent mechanism for self-loading firearms



April 14, 1953 H. H. sEFRlEDIlI CARTRIDGE DETENT-MECHANISM FOR SELF-LOADING FIREARMS 3 Sheets-Sheet l Filed NOV. 8, 1950 April 14, 1953 H. H. sEFRlED 11 CARTRIDGE DETENT-MECHANISM FOR SELF-LOADING FIREARMS 3 Sheets-Sheet 2 Filed Nov. 8. 1950 5% IM??? :E

April 14, 1953 H. H. sEFRlED 1I CARTRIDGE DETENT-MECHANISM FOR SELF-LOADING FIREARMS 5 Sheets-Sheet 3 Filed NOV. 8, 1950 hm am FM o: b@

Patented Apr. 14, 1953 UNITED CARTRIDGE DETENT MECHANISM FOR SELF-LOADING FIREARMS Harry H. Sefried II, New Haven, Conn., assignor to Olin Industries, Inc., New Haven, Conn., a

corporation of Delaware Application November 8, 1950, Serial No. 194,603

14 Claims.

This invention relates in general to improvements in self-loading or magazine firearms and more especially to the cartridge detent-means for such firearms.

An object of the invention is to provide a selfloading rearm with superior cartridge detentmeans of relatively-simple, reliable and durable construction.

A further object of the invention is to provide a superior cartridge cut-ofi for self-loading rearms for alternately detaining and releasing successive cartridges being fed from the magazine to the chamber of the barrel.

A further object of the invention is to provide a self-loading firearm with superior cartridge cut-off means which is operable in the manner described above, as the result of the movements of the breech-bolt of the rearm.

A still further object of the invention is to provide a self-loading firearm with superior cartridge cut-ofi' means, wherein the functions of alternately detaining and releasing successive cartridges and elevating the cartridges successively into chambering position, are controlled by a common resilient means.

Other objects and advantages will appear to those skilled in the art from the following, considered in conjunction with the accompanying drawings.

In the accompanying drawings, in which certain modes of carrying out the present invention are shown for illustrative purposes:

Fig. 1 is a broken view in central, vertical, longitudinal section of the mid-portion of a magazine or self-loading firearm embodying the present invention, the breech-bolt being shown in breech-closing position;

Fig. 2 is similar to Fig. 1 but shows the breechbolt in its partially-retired position;

Fig. 3 is a bottom plan view of the portion of the firearm shown in Figs. 1 and 2;

Fig. 4 is a transverse section of the rearm on line 4 4 of Fig. l;

Fig. 5 is a transverse section of the rearm on line 5-5 of Fig. 1;

Fig. 6 is a broken plan view of the underside of the breech-bolt of the firearm;

Fig. '7 is a perspective view of the magazinethroat unit of the firearm;

Fig. 8 is a perspective view of the cartridge cut-off means and cartridge-elevating means secured together in a sub-assembly;

Fig. 9 is a 'perspective View of the spring associated with the sub-assembly of Fig. 8;

Fig. l0 is similar to Fig. 2, but shows the lastremaining cartridge in the magazine'advanoed onto the elevator by the cartridge-follower; and

Fig. 11 is a perspective view of the cartridgefollower of the tubular magazine.

The particular type of firearm herein chosen for the purpose of illustrating the present invention is of the self-loading type, that is to say, it is a rearm in which the discharge of one cartrdge eiiects the extraction and ejection of the just-fired cartridge and the insertion of a fresh cartridge into the chamber of the barrel. The present invention, however, is not limited to firearms of the self-loading type, but is applicable to various types of repeating firearms and in particular, repeating firearms of the tubular maga'- zine type, as will be apparent from the following description.

Since the invention is related substantially in its entirety to the portion of the rearm located between the cartridge-chamber of the barrel and the rear end of the receiver only this limited portion of the firearm is shown in the drawings. For a more comprehensive View of the firearm, reference may be had to the Burton Patent No. 2,267,D'78, December 23, 1941.

Referring to the drawings, the receiver of the firearm is indicated at I5 and the barrel I6 is rigidly coupled to the forward end of the receiver I5 in any approved manner such, for instance, as by threading the rear end of the barrel I5 into the internally-threaded forward end of a breech-bolt passage I'I, which extends longitudinally throughout the length of the receiver I5. The barrel I5 is formed with the usual longitudinal bore, having at its rear portion a cartridgechamber I9.

Mounted for reciprocating movement in the axial breech-bolt passage I'I of the receiver I5, is a breech-bolt 20 which is yieldingly urged forwardly into its breech-closing position by a helical breech-bolt return-spring 2|. The latter presses at its forward end against the rear end portion of the breech-bolt, the rear end of the breech-bolt return-spring being seated against a removable receiver plug (not shown) in the manner shown in the above-identified Burton patent. As previously stated, the firearm is of the selfloading type and, hence, its breech-bolt 20' is adapted normally to be moved rearwardly automatically by the explosive force of a just-fired cartridge from its breech-closing position; and to be returned from its rearward excursion forwardly into breech-closing position by the force of the compressed return-spring 2 I. As is characteristic of firearms of this type, the breech-bolt may be provided with a finger-piece (not shown) for manually opening the breech. The spring 22 is the firing-spring, which is adapted in the usual manner to actuate a firing-plunger (not shown) carried by the breech-bolt.

As shown especially well in Fig. 6, the breechbolt 201s formed on its underface adjacent and intersecting its forward endzwith .a relativelyshallow but wide clearance-groove, the bottom of which is indicated at 23, the rear end of the clearance-groove 23 being blended into the underside of the rear end-portion 'ef'the'bolt a substantially-cylindrical surface of revolution. The clearance-groove 23 provides clearance beneath the underside of the forward .endfportion of the breech-bolt for accommodating the forward end of the magazine-throathereinafter .described.

Formed in the bottom 23 of the clearancegroove of the breech-bolt adjacent opposite sides :thereof and ...extending longitudinally .of Athe :breech-.bolt :rearwardly I.from 'its front facev is a painof.relatively-narrowvgrooves 24 :and 251espectively, each of .which `provides .clearance `for Athe .fupstanding Yside walls respectively of .the ,aforesaid rmagazine-throat, as Aand for the pur- )..pose hereinafter described. .Moreover, the .bot- .tom .ofthe clearance-grooveZ is,'in turn, pro- .vided .with .a 4relatively-.deep narrow ej.ector. v.groove 226 .which .extends 'longitudinally .of fthe '.clearanceegroove .1125..and upwardly .at an .oblique angletothe bottom surface thereof .so .as to pro- `vide -.c1earance .for 'the .cartridge-ejector .element of, .theemagazine-.throat "Theorward .end .ofthe .ejector-groove ,Zfintersects .the 'front' face .of the breech-bolt, while .the .rear .end .of the ejectorgroove 26 terminates short of the rear .end of rthe:clearance-.groove 25. Each.clearancegroove -ZLand 1.5.exce.eds,cin..length,.thelength of the .clearancegroove.2,3 .inthe .bottom of the breech- .bo1t,..the .rear .rend-.extensions .of .the respective Lclearanceegrooves 24.' .and 25 .constituting sub- ;Stantially-.fiat .cut-off .hold-.downisurfaces .each .of whiehis joined tottheiorwardfendiof lits lespective clearance-groove .by .a Vcylindrical `.surifacebf revolution, which .cylindrical .surfaces o'f mevolutionrconstitute relatively-shallow cartridge .cut-.off actuating-.cams 2l and `Zrespectively, as .andfor .the...p11rpose.hereinaiter described.

The, tubular AIrifagarine .of .thejrearm is .sup- .ported ,in itsstcok .in .the .manner .shown especially -.well .in the aforementioned '.Bur'ton patent, andcomprises a .tubularfhousingemember .29. and a tubular cartridge-receivilflg .member .3.0. .'tting withinthe tubular housing-.member 29 .and provided adjacent its forward end with an internal .circumferential .cartridge-follower stop-shoulder 2, .in-,a .manner common vin .tubular-magazine .learms Within the-tubular cartridge-receiving member .is alhelical/magazine-spring 3| ywhich ...exerts .constant forward .pressure upon 4a cartridge-follower .32.which, in turn, is adapted to .thrust forwardly upon such cartridges .as .may .be .withinfthe.cartridge-receiving.member 3Q; and within .the magazine-throat. indicated generally `at.- 33, aswell ascertain of those .cartridges en .route to the.cartridge-chamberv I9 of the firearm, k,all in a manner asV will .more .fully hereinafter appear.

The. Ytubular housing-.member A29 `of the maga- ;zineisformedat vitsfront end with a forwardly- .projectinglip 34 .which projects beyond the vfor- `wardendof the tubular cartridge-receiving mem- .ber and serves .to support, .the underside of the .rear .endof .a tubular extension 13.5 of the 4 aforesaid magazine-throat 33. The tubular cartridge-receiving member 3U is thus maintained in axial alignment with the tubular extension of the magazine-throat to ensure the passage of cartridges from the tubular magazine into the magazine-throat.

rIhe .magazine-throat 33 embodies the aforezsaid tubularzextension f'havingfgat its forward end two integral substantially-parallel laterally- .spaced upstanding side walls 36 and 31 respectively formed of substantially-flat metal stock, `which provide therebetween a cartridge-pocket in which each successive cartridge is supported im- .mediately prior .to .movement thereof into its chamberedjposition in the barrel of the rearm.

.Projecting inwardly from the upstanding side walls 3.6 and 31 respectively of the magazine- 'throat-"are-'shouldersf3B and 39 respectively which extend forwardly and upwardly, the lateral spacing between the forwardly-and-upwardly-inclined shoulders being onlyslightlygreater .than

the diameter of a cartridge-case,lbut'less than vber of the magazine-throat comprises a substantially U-shaped'resilient wire element arranged .to clip onto the vmagazine-.throat intermediate its .cartridge-.elevating shoulders and the cartridge-elevating .surface thereof. irEach arm "4| of 'the cartridge-.retornos.member comprises a .pair .of :spaced-parallel spring-tenmered. wires which extend upwardly 'on the outsides of the respective side walls of the magazine-throat, each pair of wires being .joined integrally at 'their upper ends by an inwardly-curved reach fof wire providing ahold-down finger 42 which lprojects laterally into the upwardly-opening cartridge- .pocket of the magazine-throat, in the manner shown especially well in Fie.- 5the lateral-.spacing between the Yirlwarcilyf.projecting hold-down fingers 421-42 .being .normally lessl than the diameter of a cartridge, `for resiliently holdinga cartridge "temporarily .against moving upwardly out of the magazine-throat, following the in itial rearward .eXcursion of Athe .breech-bolt. Formed integrally with the side wall '.31 of .the .magazine-throat and'projectin'g upwardly there- 'from and inwardly at anacute angle to the vertical plane of the side wall is .a .cartridge-ejector lip 44 which is adapted to project into the aforesaid ejector-.groove 2B in the breech-bolt 2o, as illustrated especially well in Fig. v5.

The magazine-throat 33, as well as the forward portions of the tubular housing-member 29 and the cartridge-receiving member 30, is received in a longitudinal opening 45 in the lower wall of the receiver l5, the magazine-throat vand the parts carried thereby being rigidly coupled tothe receiver partly in the longitudinal opening 4.5 therein and partly within the breech-bolt .passage Il by 4means of a coupling-pin 46 which extends transversely through axially-aligned aperture'sin the forward ends of the respective side walls of the magazine-throat and the adjacent flankingportions of the receiver.

The cartridge detent-means and elevatingmeans for alternately detaining and releasing successive cartridges from the tubular magazine into the magazine-throat and lifting cartridges successively into cliambering position is illustrated especially well in Fig. 8 and comprises a cartridge cut-olf indicated generally at 41; and a cartridgeelevator 48. The cartridge cut-off comprises, in the main, two sheet-metal arms Afl-49 supported in substantially-vertical laterally-spaced parallel relationship by an integral bottom-wall portion 55 joined to the bottom edges of the respective arms adjacent the rear ends thereof. Upstanding from the bottom-wall portion of the cut-off between its arms 49-139 and extending transversely thereof is a substantially-vertical cartridge cut-off lip 5| for alternately detaining and releasing successive cartridges being advanced into the magazine-throat, as hereinafter described. Extending upwardly from the upper edge of the arms iig-49 of the cut-off adjacent its rear end are upstanding carrier-actuating tongues 52-52 respectively which are adapted to engage the aforesaid cut-olf actuating cam-surfaces 2l' and 28 respectively of the breech-bolt, to depress the lower end of the pivoted cut-off as the breechbolt is moved into breech-closing position; the respective iiat hold-down surface rearwardly of each cam-surface serving to engage the corresponding tongue of the carrier to positively hold the cut-off in its depressed inoperative position when the breech-bolt is in breech-closing position.

The cartridge cut-off 47 and the cartridge-elevator 48 mounted thereon, as hereinafter described, is adapted to be pivotally mounted on the receiver for movement in a substantiallyvertical plane, and to this end, the forward ends of the respective arms @J9-@S or the cut-off are provided with axially-aligned apertures extending transversely therethrough and arranged to receive the coupling-pin i6 of the magazinethroat. In this connection, the lateral spacing of the arms 139-49 of the cut-olf is slightly greater than the distance between the outer faces of the side walls 36 and 3i of the magazine-throat, whereby upon assembling the cut-off and magazine-throat on the receiver the respective arms L9-49 of the cut-off will be disposed outside of the respective side walls of the magazine-throat. Moreover, the arms #iQ-49 of the cut-off are of such length that in assembling the cut-ofi and magazine-throat on the receiver, the bottom wall 50 of the cut-off is located below the tubular extension 35 of the magazine-throat whereby pivotal movement of the cut-off in a vertical plane will move its cartridge cut-olf lip 5l toward and away from the tubular extension of the magazine-throat. To this end, the tubular extension 35 is provided in its underside with a transversely-extending slot 53 which is substantially opposite the cartridge cut-off lip 5l of the cut-off and is dimensioned to permit the cartridge cutoff lip to pass upwardly therethrough into the path of movement of cartridges being fed from the tubular magazine into the magazine-throat for alternately detaining and releasing successive cartridges.

The aforesaid cartridge-elevator 48 comprises a length of nat, narrow relatively-stiff metal provided at its rear end with an apertured enlargement 54 which is dished to provide a raised bearing-surface adapted to engage against the underside of the bottom wall 50 of the cut-o, as shown in Figs. l and 2. Fastening-means is provided to secure the apertured enlargement 54 of the cartridge-elevator to the bottom wall 50 of the cut-olf rearwardly of its cartridge cut-oil' lip 5I and is preferably a rivet 55, which engages loosely in the apertured enlargement 54 at the rear end of the cartridge-elevator 48 so that while the cartridge-elevator and cut-oif form a sub-assembly, the cartridge-elevator is not fastened rigidly to the cut-01T. As shown in Fig. 8, the forward reach of the cartridge-elevator extends forwardly and upwardly between the oppositelydisposed arms 49-49 of the cut-olf and is provided at its forward extremity with a flat cartridge-supporting surface 56 which is located intermediate the cartridge-elevating shoulders 323-38 and the cartridge-elevating surface 40 of the magazine-throat for substantially vertical movement, as seen in Figs. 1 and 2, and as hereinafter described, between the respective side Walls 35 and 37 of the magazine-throat.

The cartridge cut-off 41 and cartridge-elevator i8 are adapted to be held in normal positions for respectively detaining a cartridge in the magazine-throat and supporting a preceding cartridge in an elevated position therein for chambering, by means of a single resilient element which, as .shown especially well in Fig. 9, comprises a spring 57 consisting of two reaches 58--58 of spring-tempered wire arranged in substantiallyspaced parallel relationship and joined together at their rear ends by an integral cross-piece 5B. The forward ends of the spring-tempered reaches 55-58 are bent to form upstanding inverted substantially V-shaped loops Bil-BEI rearwardly of the forward terminal-ends 6|6| of the respective reaches, the forward terminal-ends of which are substantially in the plane of the reaches 5S-58- As shown especially well in Figs. l, 2 and 3, the spring 5l is assembled in the opening 45 in the receiver for cooperative engagement with the cartridge cut-olf 41 and cartridgeelevator 48. To this end, the V-shaped loops 60 of the reaches of the spring are inserted between the corresponding side walls 38-31 and the arms 35H49 of the assembled magazine-throat and cut-off respectively, as shown especially well in Fig. 3, and held therein by means of the coupling-pin 46 which extends through the loops Sii-S5 of the reaches 58--58 of the spring. In this connection, the forward terminal-ends fil-5l of the reaches of the spring are engaged beneath the underside of the receiver adjacent the forward edge of the opening t5 therein; while the cross-piece 59 of the spring is adapted to engage against the underside of the cartridgeelevator forwardly of its connection with the pivoted cut-off, the spring temper of the respective reaches of the spring serving to constantly urge the cross-piece of the spring upwardly against the underside of the cartridge-elevator. Thereby an upwardly-directed force is exerted on the rear end-portion of the pivoted cut-off to constantly urge the latter upwardly within the receiver-opening 45, in which position its cartridge cut-olf lip 5| projects upwardly through the transverse slot 53 in the underside of the tubular extension of the magazine-throat, as shown in Fig. 2, into the path of cartridges being fed therein from the tubular magazine. The force of the carrier-spring 57 likewise serves to resiliently but independently urge the flat substantially-horizontal cartridge-supporting surface 56 of the cartridge-elevator upwardly con;

astantly within thecartridge-receiving Vpocket -of the :magazine-throat. .Moreoven it will be clear,

`gfrorrrlig. 2, that when 'the .rear'end of the cartridge cut-off is Aforced downwardly to its positionfa's shown in Fig. .1 against the resistance lof .the spring l, the cartridge .cut-off lip 5l will -be moved down out fof ,the path of lcartridges 'beingifed therein. However, since thecartridgeelevator is .mounted y'on the rear end of the cutoff by 'a loose connection, the spring continues to urge lthe .said elevator upwardly irrespective .of the downward displacement ofthe cartridge .cut-off.

:As has been pointed out above, the cartridgecutoff 4l .is'pivotallysecured at its forward end .by the coupling-pin 45 to the frame of the firearm. Therefore, the fdistance from the back Yface ofthe cartridge cutoff-lip 5| .to the couplingkpin is jalwaysvconstant and, as shown in Fig. l0, ris substantially equal to the .length of two Vcartridges -minus the thickness of .the rim of one cartridge. Y.This construction is used, in con- .junction with the .cartridge follower, .to insure `that the .last cartridge in the .magazine will be fed .into chambering position, the -aforesaid cartridge-follower 32 being constructed as hereinafter described so as -to be moved `forwardly in the Atubular magazine sufficiently to push the last cartridge in the magazine onto the cartridgesupporting surface ofthe elevator in position foi` chambering by the breech-bolt. It is also important that the forward end of the cartridgefollower be prevented from moving .forwardly-so far Vas to interfere with the underside of the breech-bolt.

To these ends, the cartridge-follower 32, in addition rto having a conventional annular flange 63 .adjacent itsrear end to `serve as a spring- .abutment and to cooperatively engage with the stop-shoulder $2 of .the receiving-member 3Q to limit .the forward movement of the cartridge- Yfollower, isconstructed at its forward end to simulate a cartridge, that isy to say, the forward end of the cartridge-follower has a rounded nose 64, while ,rearwardly thereof at a distance substantially equal to the distance between the nose of a cartridge and its rim is an annular flange 65, the front face of which is provided with a substantially-square shoulder 66 adapted to be engaged by the cartridge cutoff-lip 5l, when the latter is in its cutoff position, to positively hold the follower against forward movement. Since vthe distance from the connecting-pin 4E to the cartridge cutoff-11pm is constant, the foremost position of the roundednose E4 of the cartridge- Lfollower is thus accurately maintained, thereby insuring that .the .last .cartridge inthe magazine will be 'properly positioned on the elevator for chambering This construction has the added advantage lof eliminating inaccuracies which arise in conventional cartridge-follower stopmeans due to an accumulation of tolerances.

Moreover, as shown especially Well in Fig. 10, the spacing Vof the front and rear flanges 65 and 63, respectively, of the cartridge-follower is such that when the square shoulder 66 of the front flange 65 is in engagement with the cutoff-lip 5I,

the rearlange 63 of the cartridge-follower is vspaced rearwardly of the cartridge-cutoff stopshoulder 62 of the magazine-member 30. Thus, vwhen the cutoff-lip 5I is moved downwardly out of engagement with theflange 65 of the cartridgefollower by movement of the breech-bolt linto breech-closing position, as hereinafter described, the cartridge-follower is released Iand -*will -be 'moved forwardly bythe :force `of the followerspring until the rearmost flange A(Si) vof rthe cartridge-follower engages the stop-shoulder '62 -lof the magazine-member 3D, which thereby positivelyjprevents further forward movement of the follower. In this connection, the forward flange 65 'of the follower will have gone beyond the cutolf-lip and, consequently, to facilitate loading the magazine, the back face of the follower-flange 65 is provided with a frusto-conicalcam-surface 65 which is adapted to cam the elevated cutofflip 5l downwardly so as to permit the flange`65 of the cartridge-follower to be moved rearwardly thereof.

For `the purpose of making clear the operation of .the tubular-magazine repeating firearm above described and illustrated .in the accompanying drawings,v let it .be assumed that the cartridge c in the chamber of the barrel has just been discharged and that the parts of the firearm` are in the positions in which they areshown in Fig. .1, which illustrates the .conditions existing immediately following the discharge of the firearm.

The breech-boltis .thus in its forward .breechclosing position wherein the .flat cartridge-cutoff holddown surfaces of the respective clearancegrooves 24 and 25 of the .breech-bolt are in engagement with the upstanding tongues 52-52 of the respective arms of the cutoff and serve to hold the latter down in its inoperative position against the resistance of the spring 51, in which position the cartridge cutoff-lip 5l of the cutoff is displaced downwardly out of the path of movement of the cartridges in the tubular extension of the magazine-throat. The 'magazine-spring 3| is thus free to thrust the cartridge b, as well as the companion cartridge a, forwardly until the foremost cartridge b is checked by engagement of its forward end with the cartridge-elevating surface l0 and the underside of the breech-bolt. It will be noted, however, that when the cartridge 'b is thrust forwardly by the force of the magazinespring, the cartridge b overrides the upwardlybiased cartridge-supporting surface 56 of the cartridge-elevator and positively displaces the latter downwardly against the resistance of the tensioned spring 57.

With the parts in the positions above referred to, the breech-bolt 20 and its associated parts will be thereupon kicked back by the energy developed by the discharge of the cartridge ein the chamber of the barrel, with the effect of extracting the now-fired cartridge c from the chamber of the barrel and withdrawing the cartridge c rearwardly until it is brought into engagement with the xed upstanding ejector-lip 44 which serves to eject the cartridge from the ejectionport in the side of the receiver.

Very shortly after the initiation of the rearward travel of the breech-bolt, as above described, the fiat hold-down surfaces of the respective clearance-grooves 24 and 25 will have moved rearwardly out of engagement with the upwardly-projecting cutoff actuating-tongues 52-52, thereby releasing the latter, whereupon the force of the tensioned spring 51 will swing the cutoff upwardly as shown in Fig. 2, wherein its cartridge cutoff-lip 5l will rise up through the transverse aperture 53 in the underside `of the magazine-throat into the path of the cartridges therein, the disposition of the cartridge-cutoif with respect to the space provided forwardly vthereof .in the cartridge-pocket of the magazinethroat being such that the cutoffwill engagein front .of the .head .(or rim) of the cartridge a.

concurrently, ,the foremost .cartridge b will have beenzreleasedfor upward movement by therearf wardly-moving breech-bolt, whereupon the force of the magazine-spring acting through the cartridge a against the rear end of the foremost cartridge b, serves to urge the latter forwardly slightly. At the same time, the spring-biased cartridge-elevator 48 is now able to raise the cartridge b upwardly, the forward and upward movement of the cartridge b being controlled by the cartridge-elevating shoulders 38 and 39 and the cartridge-elevating surface d of the magazine-throat. The upward movement of the cartridge b is, however, temporarily halted by engagement of the cartridge with the resilient cartridge hold-down fingers Z-liZ projecting inwardly laterally over the open upper end of the magazine-throat. The cartridge b is thus held in an elevated position such as to have its rear face engaged by the forward face of the breechbolt when the same moves forwardly, as will presently be described.

Y When the breech-bolt has reached the limit of its rearward travel and the energy developed by the just-fired cartridge c has expended its force, the breech-bolt return-spring will assert itself and move the breech-bolt forwardly.

,The forward travel of the breech-bolt will first bring its forward face into engagement with the rear face of the now-partially elevated cartridge b and the continued forward movement of the breech-.bolt will force the cartridge b forwardly and upwardly under the guidance of the cartridge-elevating shoulders and the cartridgeelevating surface of the magazine-throat. This forward and upward movement of the cartridge b overcomes the restraining action of the cartridge hold-down fingers 42-2, whereupon the cartridge b will escape thereby under the upward urge of the spring 51 up into the cartridgechamber of the barrel. Prior to the chambering of the cartridge b, the cartridge a will still be held from moving forwardly in the magazinethroat by engagement of the cartridge-cutoff with the head of the cartridge a, as hereinabove described. However, as the breech-bolt moves into its foremost closed position for chambering the cartridge b, the cartridge-cutoff actuatingcams 21 and 28 of the breech-bolt engage the upstanding tongues 52-52 of the pivoted cutoff and force the latter downwardly against the resistance of the spring 51, thereby withdrawing the cartridge cut-off lip down out of the path of the cartridges in the magazine-throat, so as to release the cartridge a and the cartridge-follower to the rear thereof. Hence, the cartridge a will move forwardly under the urge of the magazinespring until it is checked by engagement with the forward portion of the underside of the nowclosed breech-bolt and the inclined surface 4B, the cartridge a overriding the substantiallyhorizontal cartridge-supporting portion of the cartridge-elevator, and forcing the latter downwardly against the resistance of the spring 51.

The parts of the firearm are now in position for discharging the cartridge b, upon which occurrence, the cycle above referred to will be repeated with the cartridge a now moved forwardly onto the elevator by the cartridge-follower and retained against forward and upward movement by the underface of the forward portion of the breech-bolt. The flange 65 of the cartridgefollower is now substantially opposite the cartridge cutoff lip I which, in turn, is held down out of the slot of the tubular extension 35 of the magazine, in the manner shown in Fig. 1.

Following discharge of the cartridge b and l0 rearward movement of the breech-bolt for ex'- tracting and ejecting the fired cartridge, the cartridge-cutoff is released, whereupon the force of the spring 51 urges the cartridge cutoff-lip upwardly into the path of movement of the follower for engagement with the square shoulder 66 of its flange 65, whereby the follower is held from moving forwardly. Subsequently on the forward movement of the breech-bolt, it picks up the cartridge a and moves it forwardly into the chamber of the barrel. Concurrently, the cartridge-cutoff is again forced downwardly by the forwardlymoving breech-bolt, whereby the cartridge cutoff-lip of the carrier is moved downwardly out of engagement with the square shoulder 66 of the cartridge-follower. The latter is thus released and moved forwardly by the force of the magazine-spring until the flange 63 of the follower brings up against the stop-shoulder of the magazine, thereby positively preventing further forward movement of the follower, as a consequence of which the nose of the cartridgefollower is held from interfering with the actionI of the bolt.

Upon withdrawing the tubular magazine ofV the rearm for the purpose of reloading, the

frusto-conical cam-surface 6B of the cartridge-,-

vention is of simple and durable construction and especially convenient for assembly, and is characterized by the use of a single resilient element for biasing the cartridge-cuto means and cartridge-elevator.

While the description of operation above given has been in connection with the automatic functioning of the firearm shown herein, it may here be noted that the breech-bolt and the parts carr1ed and controlled thereby may be manually shifted by force applied to a nger-piece for operating the breech-bolt.

The invention may be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention, and the present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are ntended to be embraced herein.

I claim:

1. In a repeating-rearm construction, including in combination: a receiver; a barrel having a cartridge-chamber rearwardly thereof; a breech-bolt movable in said receiver; a magazine positioned below said cartridge-chamber and extending rearwardly of the gun, said magazine having resilient means for urging cartridges therein successively upwardly and forwardly into position adjacent the cartridge-chamber of the barrel; cartridge-detent means cooperatively associated with said magazine and movable to and from the path of movement of the cartridges in said magazine to alternately detain and release successive cartridges being moved forwardly therein; cartridge-elevating means carried by said detent-means and arranged to elevate a cartridge in said magazine into position to be engaged by said breech-bolt for insertion into the chamber of the barrel; and resilient means constructed and arranged to hold both said detentmeans and said elevating-means in theirV respective positions for detaining a cartridge from moving forwardly in said magazine and for elevating a cartridge into chambering position; said detent-means being so positioned that, when moved into cartridge detaining position, the pressure of said magazine resilient means is removed from the cartridge about to be chambered prior to elevation of such cartridge into final position for chambering..

Y 2. In a repeating-firearm construction including in combination: a receiver; a barrel having a cartridge-chamberrearwardly thereof; a breechbolt movable in said receiver; a magazine positioned below said cartridge-chamber and extending rearwardly of the gun, said magazine having resilient means for urging cartridges therein successively upwardly and forwardly into position adjacent the cartridge-chamber of the barrel; cartridge-detent means cooperatively associated with Said magazine and movable toand from the path of movement of the cartridges in said magazine to alternately detain and release successive cartridges being moved forwardly therein.; cartridge-elevating means carried by said detentmeans and arranged to elevate a cartridge in said magazine into position to be engaged by said breech-bolt for insertion into the chamber of the barrel; resilient means constructed and arranged to holdboth said detent-means and said elevating-means in their respective positions for detaining a cartridge from moving forwardly in said magazine and for elevating a cartridge into chambering position; hold-down means carried by said magazine and arranged to-temporarily resist the upward movement of a cartridge by said elevating-means into chambering position; said detent-means being sopositioned that, when moved into cartridge detaining position, the pressureof said magazine resilient means is removed from the cartridge about. to be chambered prior to elevation of such cartridge-into final position for chambering.

3v; In a repeating-firearmY construction, including in combination: a receiver; a barrel having a cartridge-chamber; a breech-bolt movable in saidV receiver; a magazine positioned to extend below said receiver and constructed and arranged tolsuccessivelycause cartridges to be moved upwardly and forwardly into position adjacent the cartridge-chamber of the barrel; cartridge-detent meanslcooperatively associated with said magazine andmovable to and from the path of movement of the cartridges in saidmagazine to alternately detain and release successive cartridges being moved forwardly therein; cartridgeelevating means carried by said detent-means and arranged to elevate a cartridge in said magazine into position to be engaged by said breechbolt for insertion into the chamber of the barrel; resilient means constructed and arranged to hold both saiddetent-means and said elevating-means in their respective positions for detaining a cartridge from moving forwardly in said magazine and' for elevating a cartridge into chambering position; and a single fastening-element constructed and arranged to engage and secure said magazine, said cartridge-detent means and said resilient means to said receiver.

4. In a repeating-firearm construction, including; in combination: a receiver; a barrel having a..cartridgechamber; a breech-bolt movable in said receiver; a magazine positioned to extend below said-receiver andconstructedand arranged tosuccessively cause cartridges .tobe moved up and resilient cartridge vvardly` and forwardly intopositiorr adiacnt'the; cartridge-chamber of the barrel; cartridge-datent, means cooperatively associatedv with. said maga:- zine and movable to and from'thel path of' movement of the cartridges in said magazine to: alternately detain and release successive cartridges: being moved forwardly therein; cartridge-elevating means `carried by. said detent-means;-alvidparf-v ranged to elevate a cartridge in said magazine.' into position to be engagedV by, saidfbreech-bolt: for insertion into the chamber ofthe barrels;- re.- silient means constructed. and; arranged togholid: both said detent-means and saidelevating-means in their respective positions for detaining' a" cartridge from moving forwardly' in said'..magazine, and for elevating a cartridge into chamltvering4 position; resilient cartridge. hold-down means; carried by said magazine and arranged totem-r porarily resist the upward movement` of: a. cartridge by said elevating-means` into cha-mberng.` position; and a single fastening-elementiconstructed and arranged` to engage and securesaid magazine, said cartridge-detent means andi said resilient means to said receiver.

5. In a repeating-firearm construction, includ.-d ing in combination: a receiver; a lbarrelhaving a cartridge-chamber; a breech-bolt movable. in. said receiver; a tubular magazinapositioned be-l low said cartridge-chamber toextend rearwardly. of the gun, said tubular magazine havingfa; magazine-throat at its upper end and aA magazine-spring at its lower end, said magazinespring being arranged to successively;cause-'car-` tridges in said tubular magazine toY De-moved upwardly and forwardly into said magazine-- throat intoV position adjacent the cartridge chamber of the barrel; cartridge-detent*meanscooperatively associated with said magazine-- throat and movable to and fromV the path of movement of the cartridges in saidv magazinethroat to alternately detain andrelease succes-- sive cartridges being moved forwardly therein; cartridge-elevating meansarrangedy to project into said magazine-throat to elevate'a cartridge therein into position to be engaged; by" said` breech-bolt for insertion into the chamber of'v the barrel; and resilient means1 constructed and arranged to hold both said detent-means andi said elevating-means in theirv respectivev posi-- tions for detaining a cartridge from movingfore wardly in said magazine-throat andv forelevat ing a cartridge into charnberingv position; said-y detent-means being 'so` positioned that; when' moved into cartridge detainingposition, thepres-v sure of said magazine-springisV removed from'A the cartridge about to berchambered*prior'to-elevation of such cartridge into final position for chambering.

6. In a repeating-firearm construction; include' ing in combination: a receiver.; a barrelhavinga cartridge-chamber; a breech-bolt movable` insaid receiver; a tubular-magazine positioned below said cartridge-chamber to extend rearwardly of the gun, said tubular magazine having amaga-V zine-throat at itsY upper end and' a magazine--A spring at its lower end, said magazine-spring loe-- ing arranged tosuccessively causel cartridges. in saidtuloularA magazine to be movedupwardly and" forwardly into said magazine-.throat` into posi-y tion adjacent the cartridge-chamber offthe..ba.i.-v rel; cartridge-detent4 means cooperatively, asso.t ciated with said magazine-throat and; movable... to and fromthe path ofA movementofthe car-- tridges inv said magazine-throat.. to.v alternately,v detain and releasel successive cartridges being moved forwardly therein; cartridge-elevating means arranged to project into said magazinethroat to elevate a cartridge therein into position to be engaged by said breech-bolt for insertion into the chamber of the barrel; resilient means constructed and arranged to hold both said detent-means and said elevating-means in their respective positions for detaining a cartridge from moving forwardly in said magazinethroat and for elevating a cartridge into chambering position; and resilient cartridge holddown means carried by said magazine-throat and arranged to temporarily resist the upward movement of a cartridge by said elevating-means into chambering position; said detent-means being so positioned that, when moved into cartridge detaining position, the pressure or" said magazinespring is removed from the cartridge about to be chambered prior to elevation of such cartridge into final position for chambering.

7. In a repeating-firearm construction, including in combination: a receiver; a barrel having a cartridge-chamber rearwardly thereof; a breech-bolt movable in said receiver; an actuating cam on said breech-bolt; a magazine positioned below said cartridge-chamber and extending rearwardly of the gun, said magazine having resilient means for urging cartridges therein successively upwardly and forwardly into position adjacent the cartridge-chamber of the barrel; cartridge-detent means comprising a cartridge cut-off cooperatively associated with said magazine and having a cartridge cut-off lip and a cam-engaging element, said cam-engaging element being arranged to be engaged by the actuating-cam of said breech-bolt as said breech-bolt moves into breech-closing position to move said cartridge cut-off lip down out of the path of movement of the cartridges in said magazine so as to release successive cartridges being moved forwardly therein; cartridge-elevating means carried by said cartridge cut-off and arranged to elevate a cartridge in said magazine into position to be engaged by said breech-bolt for insertion into the chamber of the barrel; and resilient means arranged to engage said cartridge-elevating means to resiliently hold the said cartridge cut-off lip up in the path of movement of the cartridges in said magazine to detain successive cartridges being moved forwardly therein, and to resiliently hold said elevating-means in its u p position for elevating a cartridge into chambering position; said detent-means being so positioned that, when moved into cartridge detaining position, the pressure of said magazine resilient means is removed from the cartridge about to be chambered prior to elevation of such cartridge into nal position for chambering.

8. In a repeating-firearm construction, including in combination: a receiver; a barrel having a cartridge-chamber rearwardly thereof; a breech-bolt movable in said receiver; an actuating-cam on said breech-bolt; a magazine positioned below said cartridge-chamber and extending rearwardly of the gun, said magazine having resilient means for urging cartridges therein successively upwardly and forwardly into position adjacent the cartridge-chamber of the barrel; a coupling-pin arranged to secure the forward end of said magazine to said receiver; cartridgedetent means comprising a cartridge cut-oli pivotally supported by said coupling-pin beneath said magazine, said cut-off having a cartridge cut-off lip and a cam-engaging element, said cam-engaging element being arranged to be en- 114' gaged by the actuating-cam of said breech bolt as said breech-bolt moves into breech-closing po-` sition to swing said cut-off downwardly and move said cut-off lip down out of the. path of movement of the cartridges in said magazine so as to release successive cartridges being moved forwardly therein; cartridge-elevating means carried by said cartridge cut-off and arranged to elevate a cartridge in said magazine into posi- A tion to be engaged by said breech-bolt for insertion into the chamber of the barrel; and resilient means arranged to engage said cartridge-elevating means to resiliently hold said pivoted cut-off upwardly and the said cartridge cut-oi lip up in the path of movement of the cartridges in said magazine to detain successive cartridges be- A ing moved forwardly therein, and to .resiliently hold said elevating-means in its .up position for elevating a cartridge into chambering position; said detent-means being so positioned that, when moved into cartridge detaining position, the

pressure of said magazine resilient means is re-V moved from the cartridge about to be chambered prior to elevation of such cartridge into nal position for chambering.

9. In a repeating-firearm construction, includ-` ing in combination: a receiver; a barrel having a cartridge-chamber rearwardly thereof; a breechbolt movable in said receiver; an actuating-cam on said breech-bolt; a magazine positioned below said cartridge-chamber and extending rearwardly of the gun, said magazine having resilient means for urging cartridges therein successively up- Y wardly and forwardly into position adjacent the cartridge-chamber of the barrel; a. coupling-pin arranged to secure the forward end of said magazine to said receiver; cartridge-detent means comprising a cartridge cut-off pivotally supported by said coupling-pin beneath said magazine, said cut-oir having a cartridge cut-off lip and a camengaging element, said cam-engaging element being arranged to be engaged by the actuatingcam of said breech-bolt as said breech-bolt moves into breech-closing position to swing said cut-0E downwardly and move said cut-ofi lip down out of the path of movement of the cartridges in said magazine so as to release successive cartridges being moved forwardly therein; cartridge-elevating means carried by said cartridge cut-off and arranged to elevate a cartridge in said magazine into position to be engaged by said breech-bolt for insertion into the chamber of the barrel; and resilient means secured at its forward end to said receiver by said coupling-pin and arranged to engage at its rear end against the underside of said cartridge-elevating means to resiliently hold said pivoted cut-off upwardly and the said cartridge cut-off lip up in the path of movement of the cartridges in said magazine to detain successive cartridges being moved forwardly therein, and to resiliently hold said elevating-means in its up position for elevating a cartridge into chambering position; said detent-means being so positioned that, when moved into cartridge detaining position, the pressure of said magazine resilient means is removed from the cartridge about to be chambered prior to elevation of such cartridge into final position for chambering.

10. In a repeating-firearm construction, including in combination: a receiver; a barrel having a cartridge-chamber; a breech-bolt movable in said receiver; a tubular magazine positioned below said cartridge-chamber to extend rearwardly of the gun, said tubular magazine having a magazine-throat at its upper end providedwth...

and arranged to be urged forwardly therein by a magazine-spring, the said cartridge-follower having a flange adjacent its rear end adapted to engage the stop-shoulder of said magazine to limit the forward movement of said follower therein; cartridge-detent means cooperatively associated with said magazine and movable to and from the path of movement of cartridges in said magazine to alternately detain and release successive cartridges being moved forwardly therein; resilient means arranged to hold said detent-means in a position for detaining a cartridge from moving forwardly in said magazine; a ange on said cartridge-follower, said ange being displaced rearwardly of the forward end thereof a distance corresponding substantially to the length of a cartridge and arranged to engage said cartridge-detent means to positively limit 18 the forward movement of said cartridge-follower in said magazine independently of the said stopshoulder thereof for correctly positioning the last cartridge in said magazine for chambering by said breech-bolt; and a cam-surface on the rear face of said ange for camming said detent downwardly out of the rearward path of movement of said follower.

HARRY H. SEFRIED II.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,136,119 Reising NOV. 8, 1938 2,270,408 Burton Jan. 20, 1942 2,324,238 Reising July 13, 1943 2,369,244 Lowe Feb. 13, 1945 April 14, 1953 w. v. VELEZ ETAL ADJUSTABLE CHOKE Filed Dec. 

